The present invention relates to an optical system in a reproduction apparatus for recording a reproduced picture image of an original picture by projecting picture information on the original picture onto a photoelectrical converting elements(s) such as CCD line sensor etc. and basing on its (their) output signal(s) through a focusing optical system, and particularly relates to an apparatus for obtaining a reproduction picture image(s) of uniform picture quality by correcting unevenness in light quantity of a light quantity projected onto the photoelectrical converting element(s).